I rented last semester and didn't have a problem returning. The quality of the books was as advertised and there was no shipping delay (I purchased fairly early from sellers with lots of 5-star reviews). I tended to take notes in my own notebook then transfer them to a Word doc later, so previous users' extensive highlighting and annotations were not too irritating.

For this coming semester, I bought books for about $20 less than the Amazon rental rate off the school listserv. Pros: was able to inspect them in person before handing over cash, can probably resell later, was able to get the logistics taken care of right after exams. Cons: meeting in person over break is probably hard to arrange if you have a life.